1. Field of the Invention
The present invention relates to an innovative method for manufacturing callipers of disc brakes, in particular for motorcycles.
2. State of the Prior Art
In the motorcycle industry making monolithic callipers is known that are intended to act on the disc of the brake to achieve braking. The callipers comprise a monolithic body obtained through die-casting, which is provided with a slit that in use receives the periphery of the disc of the brake. In the body, four chambers are typically formed that are open towards the slit and face in couples opposite sides of the slit. The chambers house four corresponding pistons that hold the pads of the brake and cooperate in pairs to pinch the braking disc.
Different methods have been proposed for making this type of calliper, which are nevertheless generally complicated, costly and sometimes do not enable callipers to be obtained that are reliable in the event of high operating pressure. According to a known technique, a monolithic body is initially obtained through die-casting with two aligned cylindrical cavities, intended to make the chambers of two cylinders of the calliper on opposite sides of the slit receiving the disc of the brake.
One of the two cavities has a closed bottom, whilst the other one has a bottom with an opening passing through to the outside of the calliper, which is formed in the body to facilitate machining of the internal surfaces of the chambers.
After machining, the opening has to be closed with a cap, which can be applied to the body of the calliper in various manners, for example by screwing, or by using an elastic clip.
Known solutions for applying the cap, can, however, be unreliable in the event of great operating pressure and may require expensive machining of the workpieces.
Further, in order to obtain a good seal, it is generally necessary to use washers between the cap and monolithic body, which increases the complexity of the calliper structure, increasing the manufacturing costs of the product.
The general object of the present invention is to overcome the aforesaid drawbacks by providing a method for manufacturing callipers for disc brakes that is simple and cheap, and which enables a calliper to be obtained that provides long-term reliability and is able to support high operating pressure in the chambers.